The invention relates generally to an apparatus and method for providing continuous passive motion support to the back of a person for preventing or treating lower back pain. More particularly, the invention provides pneumatic fluid pressure means for cycling the lumbar region through a substantial range of lordosis. One or more fluid inflatable bags are cyclically inflated and deflated by means of an electrically powered pump. Programmable circuitry controls the operation of the pump by adjusting the pump supply voltage. In another embodiment, one or more of the fluid inflatable bags provide static baseline support pressure while the same or other bags provide continuous passive motion support to the back of a person.
This invention relates generally to a method and apparatus for providing continuous passive motion to the lumbar region of the spine.
The inventor herein has been issued three patents related to continuous passive motion (CPM), the teachings of which are herein incorporated by reference. U.S. Pat. No. 4,981,131 (hereinafter xe2x80x9cthe ""131 patentxe2x80x9d) disclosed apparatus for cycling the lumbar region of the spine through a substantial range of lordosis (forward spinal curvature) for the purpose of preventing and relieving low back pain. In that patent, an inflatable bladder in contact with the back is pressurized and depressurized to effect the substantial range of lordosis. U.S. Pat. No. 5,624,383 (hereinafter xe2x80x9cthe ""383 patentxe2x80x9d) disclosed an apparatus and method for providing force feedback in continuous passive motion (CPM) systems, whereby a force measuring apparatus is provided for continuously measuring the force exerted by a force-applying mechanism on a person""s lumbar area and a system controls the force exerted by the mechanism in order to build up to a predetermined upper force range, which is maintained during an xe2x80x98on cyclexe2x80x99 to provide force on the lumbar area of the user. U.S. Pat. No. 5,637,076 (hereinafter xe2x80x9cthe ""076 patentxe2x80x9d) disclosed the ability to measure and control the force applied to the person""s back throughout the inflate and deflate cycles to accommodate variations in a person""s spinal compliance, posture and position during the spinal mobilization.
As discussed in detail in the ""131 patent, research indicates that CPM of the lower back, or lumbar, region of a person through a substantial range of lordotic movement ameliorates lower back pain. Such motion is not massage, which relates merely to superficial tissues, such as might be produced by duration intervals shorter than five seconds, but constitutes motion of vertebrae with respect to one another. That patent disclosed controlling an inflation and deflation of a bladder by opening and closing two sequential valves 10, as shown in FIGS. 1a and 1b, while a pump 11 is working continuously, to control a flow of a fluid through a conduit. FIG 1a illustrates the positions of the two sequential valves 10 necessary to inflate the bladder, and FIG. 1b illustrates the positions of the two sequential valves 10 necessary to deflate the bladder.
There was no provision, however, in those patents for adjustably controlling the operation of a pump providing a cyclic pneumatic inflation pressure. The ""131 patent disclosed controlling CPM fluid flows by directing valves in the system to alternately shunt fluid from a constant pressure source (a continuously operating pump) toward and then away from the support bladder. The ""076 patent disclosed, additionally, only an apparatus for turning on a pump to increase the pressure, and turning off the pump and allowing air to flow out of the inflation bladder to induce deflation. Therefore, in order to provide maximal comfort to a user while achieving the desired ranges of spinal motion, better control of the inflation rate is needed. Furthermore, a need exists for additional means to reduce the workload of the pump in order to prolong its life while providing continuous passive motion to the lumbar region of a person.
Nor was there any a provision in those patents for providing a minimum static baseline support pressure. Through extensive experience with CPM technology, the inventor has discovered that individual users require or prefer varying amounts of maximum and minimum inflation pressures, inflation and deflation rates, and lengths of inflation and deflation cycle intervals. Need, therefore, exists to allow users to select and achieve maximum benefit and comfort by controlling cycle parameters such as the inflation and deflation rates and durations, as well as the maximum inflation and minimum baseline support pressures between which CPM would be delivered.
It is an object of the invention to address the needs described above. The invention disclosed herein is a system and method for continuous passive motion back support for a person while seated or supine. The apparatus cycles the back of the person through a substantial range of lordosis. It comprises a substantially static structure adjacent to the back of the person, a fluid-inflatable bag disposed between the static structure and the person""s back, wherein the fluid-inflatable bag includes a back-engaging surface cyclically moveable to increase and decrease the distance between the static structure and the back-engaging surface, an electrically-powered pump connected to a reservoir or the atmosphere for supplying a fluid to the fluid-inflatable bag, a conduit adapted to conduct the fluid between the reservoir or the atmosphere and the fluid-inflatable bag, and programmable circuitry for adjusting a voltage supplied to the electrically-powered pump, whereby fluid flow in the conduit is effected by adjustably operating the electrically-powered pump. The fluid is preferably air, but could comprise any gaseous or gas mixture, or any liquid, such as, for example, water.
In one embodiment, the programmable circuitry is further comprised of a control panel adapted to receive user-adjustable cycle parameters. In a preferred embodiment, the programmable circuitry adjusts the voltage supplied to the electrically-powered pump in a manner responsive to the user-adjustable cycle parameters. The user-adjustable cycle parameters could include a duration of an inflation and deflation cycle, a rate of inflation, and/or an inflation pressure. The programmable circuitry may adjust the voltage supplied to the electrically-powered pump by modulating the pulse width of the voltage. Alternatively, the programmable circuitry may adjust the voltage by use of a potentiometer.
In another embodiment, the apparatus includes a check valve to protect against inappropriate entrance of fluid into the system through the conduit. The apparatus may additionally be equipped with a valve adapted for adjustably limiting a rate of fluid flow in the conduit during inflation.
In another embodiment, the apparatus may also include a transducer adapted to monitor the force exerted by the back-engaging surface on the back of the person and to transmit an output regarding the force to the programmable circuitry. The programmable circuitry may then adjust the voltage supplied to the electrically-powered pump in response to the output transmitted from the transducer, whereby the programmable circuitry regulates the flow of the fluid in the conduit. The programmable circuitry may include a timer for timing an inflation interval and/or a deflation interval.
In another embodiment, the apparatus includes an exhaust conduit adapted to conduct the fluid between the conduit and the reservoir or atmosphere through a solenoid valve. The programmable circuitry may regulate the flow of the fluid in the exhaust conduit by additionally closing the solenoid valve, thereby regulating inflation of the fluid-inflatable bag. And the programmable circuitry may additionally open the solenoid valve, thereby regulating deflation of the fluid-inflatable bag.
Also disclosed is a method for providing continuous passive motion back support for a person, comprising the steps of: providing a fluid-inflatable bag having a force-applying portion connected to an electrically-powered pump for inflating the fluid-inflatable bag; positioning the fluid-inflatable bag behind and adjacent to the lumbar region of the person, the force-applying portion of the fluid-inflatable bag adjacent to the back of the person when so positioned; and cyclically inflating the fluid-inflatable bag by adjusting a voltage supplied to the electrically-powered pump pumping fluid into the fluid-inflatable bag and deflating the fluid-inflatable bag by allowing fluid to flow out from the fluid-inflatable bag, thereby cyclically varying forces applied to the spine of the person moving the spine through a substantial range of extents of lordosis.
In another embodiment, the invention provides a baseline support pressure while treating or preventing low back pain. In this embodiment, the invention comprises a fluid-inflatable bag having a force-applying portion, the bag adapted to be positioned behind and adjacent the lumbar region of the person, the force-applying portion adjacent to the lumbar region of the spine when the bag is so positioned, a source of fluid under pressure, a conduit adapted to conduct the fluid between the source and the bag, a control panel adapted to receive a user-selected baseline pressure, a regulator adapted for automatically controlling flow of the fluid in the conduit, the flow of the fluid cyclically causing inflation and deflation of the bag, the regulator thereby controlling the pressure of the fluid in the bag, the inflation and deflation of the bag thereby cyclically moving the spine through a substantial range of extents of lordosis, the regulator further adapted to prevent the pressure of the fluid in the bag from dropping below the user-selected pressure.
The invention may provide continuous passive motion back support by the use of multiple fluid-inflatable bags. In such an embodiment, the invention comprises a substantially static structure adjacent to the back of a person, two or more fluid-inflatable bags disposed between the static structure and the back of a person, the fluid-inflatable bags each including a back-engaging surface independently and cyclically moveable to increase and decrease the distance between the static structure and each back-engaging surface thereby to cycle the lower back through a substantial range of lordosis, a pump connected to a reservoir or the atmosphere for supplying a fluid to the fluid-inflatable bags, a number of supply conduits adapted to conduct the fluid between the reservoir or the atmosphere and the two or more fluid-inflatable bags, at least one exhaust conduit adapted to conduct the fluid between the two or more fluid-inflatable bags and the reservoir or the atmosphere, a number of solenoid valves equal to a number of the two or more fluid-inflatable bags for which independent inflation control is desired, the number of solenoid valves disposed between the number of supply conduits and the at least one exhaust conduit, and programmable circuitry adapted to control operation of the pump and independently the number of solenoid valves, thereby controlling flow of the fluid in the number of supply conduits and the at least one exhaust conduit, the flow of the fluid cyclically causing inflation and deflation of the two or more fluid-inflatable bags, the programmable circuitry thereby controlling the pressures of the fluid in the two or more fluid-inflatable bags. The pump may further comprise an electrically-powered pump supplied with a voltage. And the programmable circuitry may control the pump by either turning the pump on or off, or alternatively by adjusting the voltage supplied to the electrically-powered pump.
The multiple fluid-inflatable bag embodiment may also include programmable circuitry comprised of a control panel adapted to receive user-adjustable cycle parameters for each of the two or more fluid-inflatable bags. And the programmable circuitry may adjust the voltage supplied to the electrically-powered pump in a manner responsive to the user-adjustable cycle parameters. As in the single bag embodiments, the user-adjustable cycle parameters may include, for each of the bags, a duration of an inflation and deflation cycle, a rate of bag inflation, and/or an inflation pressure. The multiple fluid-inflatable bag embodiment may also provide a baseline support pressure by adjusting the inflation cycle of one or more of the bags to a maximum, whereby the one or more bags provides a static baseline support pressure to the back of the person, and the other bag(s) continues to provide continuous passive motion support.
In a preferred embodiment, the invention comprises three fluid-inflatable bags arranged in a layered manner perpendicular to the back of the person, wherein the middle of the three bags provides static baseline support pressure to the back of the person. Either of the outer bags, preferably the bag adjacent to the lower back of the person, may provide continuous passive motion above the baseline support pressure. The three bags may additionally be incorporated into a support structure, such as a flippable mattress.
The invention disclosed herein also includes a method for providing a static baseline support pressure during continuous passive motion for the back of a person. The method is comprised of the steps of providing a fluid-inflatable bag including a force-applying portion connected to a pump for inflating the fluid-inflatable bag with a flow of a fluid supplied from a reservoir or the atmosphere through a conduit, providing programmable circuitry adapted to control operation of the pump, positioning the fluid-inflatable bag behind the lumbar region of the person, the fluid-inflatable bag being adjacent to the lumbar region of the person with its force-applying portion adjacent to the lumbar region of the spine of the person when so positioned, inflating the fluid-inflatable bag to a desired minimum support pressure with the fluid pumped by the pump, and controlling the operation of the pump by means of the programming circuitry, thereby controlling a cyclic flow of the fluid in the conduit and a cycle of inflation of the fluid-inflatable bag and deflation to no less than the desired minimum support pressure, thereby cyclically varying forces applied to the spine of the person moving the spine through a substantial range of extents of lordosis while providing a baseline support pressure in the bag.